Injection valve for internal combustion engines



E. WXRTSEN Feb. 4, 1941.

INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES Original Filed Aug. 51, 1936 chi-05mg Patented Feb. 4, 1941 UN TED STATES INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES Ernst Wirtsen, Chester, Pa.

Original application August '31, 1936, Serial No. 98,775. Divided and this application October 14, 1938, Serial No. 235,070

2 Claims.

My invention relates to injection valves for internal combustion engines, and is especially adapted for application to two-cycle engines including those of the Diesel type.

The principal object of my invention is to provide an injection valve that will utilize the air pressure produced in the cylinder on the operation of the engine to thereby simplify operation of the valve to take the place of the complicated and expensive fuel injection pump and injection valve commonly employed in engines of this general character. v

With this principal object in view my invention contemplates a construction of injection valve to include a piston working under Spring pressure at the inner end of an opening through the wall of the engine-cylinder, in connection with a spring-actuated needle-valve controlling the opening through the nozzle from which the fuel is discharged into the engine-cylinder for a cooperation depending upon the pressure of air on the upstroke of the engine-piston; all as hereinafter fully described and more specifically set forth in the appended claims.

In the drawing:

Figure 1 is a sectional view through an injection valve constructed in accordance with my invention,showing the normal position of the valve-piston and co-acti'ng needle-valve.

.Fig. 2 is a similar view showing the position of the co-operating elements of the valve under air pressure in the engine-cylinder.

Fig. 3 is-a fragmental view illustrating the position of the valve-piston and needle-valve in discharging the fuel oil from the nozzle, and

Fig. 4 is a diagrammatic view or graph to il lustrate the operation of the injection valve.

The injection valve, in accordance with my invention, is illustrated as being located in an opening, l0, through a wall of the engine cylinder, illa instead of an independent casing, the operating parts including as essential elements a spring-actuated valvepiston provided with a discharge nozzle at the lower end thereof, and cooperating with a spring-actuated needle-valve adapted to supply the fuel mixture to a valve chamber communicating with a nozzle discharging into the combustion chamber of the engine cylinder.

The valve-piston, It, works in a bushing l2 fixed in the lower end of the opening Ill and is actuated in one direction, or towards the engine-cylinder, by a. spring l3 interposed between the piston and a cap ll closing the outer end of the opening, that end of the spring engaging the piston being preferably seated in an annular recess l5 surrounding a tubular projection l6 projecting upwardly from the center of the piston with the opening through the projection communicating at its lower end with a valve chamber I! from which a nozzle I8 projects through the inner end of the piston. The

discharge of fuel oil through the nozzle is controlled by a reciprocating valve rod l9 reduced in size and tapered at its lower end to form a plug seating within a corresponding opening in the nozzle, after the manner of a needle valve, and this valve rod is hollow from the top to near the lower end thereof to provide a passage for the fuel oil, with openings or ports extending through the opposite sides of the rod for discharging the fuel oil into the valve chamber when the ports are exposed below a sleeve 2| in which the valve rod works. For augmenting the discharge of oil from the hollow valve rod into the valve chamber said rod is provided with a circumferential recess 22, with which the openings 20 communicate, and so as not to interfere with movement of the valve-piston in the recess in the cylinder there is a vent 23 extending from the upper part of said recess through the cylinder wall to the atmosphere.

The sleeve housing the valve rod extends through the cap M and into the tubular projection l6 of the valve piston, and below the lower end of thissleeve the piston is hollowed out to provide the valve chamber hereinbefore referred to.

The operation of the valve rod in opening and closing the nozzle for discharging the fuel oil into the engine cylinder is under the control of the reciprocating valve-piston ll influenced by compression of air in the engine cylinder, and is further controlled by oil pressure in the hollow valve rod and a spring 24 hearing on the upper end thereof, with the tension of the spring regulated by an apertured plug 25 threaded into the upper end of a. nipple 26 forming a connection with a fuel supply pipe (not shown). The nipple is suitably connected to the upper end of the sleeve housing the valve rod; for which purpose the 'nipple and sleeve are provided with flanged lower ends.

In the operation of my improved injection valve the discharge of the fuel oil may be regulated in difierent ways, being effected by hydraulic pressure augmented by a spring in contradistinction to atmospheric pressure, to thereby obtain-greater flexibility of operation, with the flexible hydraulic counterpressure regulated in the usual manner by overflow valve, or any or when the piston of the engine passes the dead center, and to maintain said valve closed until the operation is repeated.

From the foregoing it will be obvious that the operation of the injection valve is controlled by the compression in the engine cylinder to thereby provide a simple and efiective means for supplying the fuel oil at the proper time, thus improving on the more expensive fuel injection pump and fuel injection valve commonly used in connection with internal combustion engines, and more especially with those of the Diesel engine type-there being no need for driving mechanism, such as a cam, cam shaft, rollers, or other complicated mechanism for transfer of motion. My improved form of injection valve also dispenses with the need of any extra reversing means, and by its use there is a uniform injection for the reason that the pressure rises in proportion to the pressure transmitted to the valve piston directly from the compression of air and fuel in the engine cylinder. valve, in accordance with my invention, is usable either in the cylinder head for two or four-cycle internal combustion engines, or in the sidewall of the cylinder in connection with opposed piston in the use of high fuel pressure, for in case the needle valve is clogged, or in the event of otherslight defect,the pump supplying the fuel oil is adjusted to correct position automatically according .to the compression in the engine-cylinder, and is likewise adjusted in response to variable barometer pressure. As the valve is operated entirely by the compression in the engine-cylinder it follows that when the pressure rises to a predetermined point immediately before the enginepiston reaches dead center on its compression stroke the needle valve is opened and when the engine-piston passes the dead center said needle valve is closed, and for a better understanding of the operation of the valve the graph, Fig. 4, indicates its functioning.Z and Y representing the full stroke and X and Y a shorter stroke.

Although I have described my invention as especially adapted for use in connection with a two-cycle engine it will be understood that its 0 application may be extended to four-cycle engines in which an injection valve of this character can be employed for supplying fuel to the combustion chamber of .the engine cylinder. v

It will be obvious, from the foregoing descripinfluence, the springs balancing the compression pressure and amount of oil injected, for the reason that the strokes of the engine piston depend on the pressure in the oil line regulated by the needle valve to keep said Furthermore, the injection.

usual governor (not shown) acting on the needle valve. When the valve in the oil line closes a little under the influence of the governor the pressure on the needle valve is less and allows the valve to stay open longer. Conversely, when the valve in the oil line is opened by the governor the pressure rises and acts on the top part of the valve open a shorter time. i

This application is a division'of my original application for patent entitled Improvements in internal combustion engines, filed August 31,

1933, Serial No. 98,775.

I claim: 1. An injection valve for internal combustion engines comprising a reciprocating piston work-v ing in a cylinder and actuated in one direction by compression within the engine cylinder, a spring actuating the piston in opposition to the compression, said piston having a recess extending into the same to near its outer end, and a nozzle in the outer end of the piston communicating with the recess and engine cylinder and having a valve seat at its inner end; together with a sleeve or stationary valve casing extending into the recess in the piston and terminating to form a fuel compression chamber intermediate the end of said valve casing and nozzle, a hollow fuel conducting piston rod extending through the valve casing and having a valve head at its outer end adapted to seat on said valve seat, the passage in the hollow piston rod communicating with ports discharging into the fuel compression chamber above the valve head and adapted to be closed by the lower end of the sleeve or valve casing, and a spring cooperating with, the oil pressure to maintain the needle valve closed during the operation of the valve piston preliminary to the opening of the valve.

2. An injection valve for internal combustion engines comprising a reciprocating piston working in a cylinder and actuated in one direction by compression within the engine cylinder, a spring actuating the piston in opposition to the compression, said piston having a recess extending into the same'to near its outer end, and a nozzle in the outer end of the piston communieating with the recess and engine cylinder and having a valve seat at its inner end; together with a sleeve or stationary valve casing extending into the recess in the piston and terminating to form a fuel compression chamberintermediate the endof said valve casing and nozzle, a fuel conducting hollow piston rod extending through the valve casing and having a valve head at its outer end adapted to seat on said valve seat, the passage in the hollow piston rod communicating with ports discharging into the fuel compression chamber above the valve head and adapted to be ,closed by the lower end of the sleeve or valve casing, a spring bearing on the upper end of ,the piston rod and cooperating with the oil pressure to maintain the needle valve closed during the operation of the valve piston preliminary to the opening of the valve, said spring being located in a tubular member connected to the aforetension of the spring acting on the valve rod.

ERNST WIRTSEN. 

